Multicolor photographic elements containing coarse-grain silver halide emulsions

ABSTRACT

Photographic elements are disclosed which comprise a support having thereon at least two image dye-providing layer units which each contain a silver halide emulsion and a color coupler. The silver halide emulsion of one of the image dye-providing layer units has a substantially larger mean grain size than the silver halide emulsion of at least one other image dye-providing layer unit and has associated therewith at least 10 mg./ft.2 of a nondiffusing anionic organic compound. The image dye-providing layer units containing a coarse-grain emulsion and the nondiffusible anionic organic compound exhibit high rates of silver formation when developed with a color-developing agent such as a p-phenylenediamine.

United States Patent Mowrey Sept. 9, 1975 [75] Inventor: Rowland GeorgeMowrey,

Rochester, N.Y.

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

22 Filed: Nov. 20, 1972 211 Appl. No.: 307,890

[52] U.S. C1 96/74; 96/68 [51] Int. Cl. G03C 1/76 [58] Field of Search96/74, 68

[56] References Cited UNITED STATES PATENTS 3,022,172 2/1962 Ohba ct a1.96/114 3,251,689 5/1966 96/74 3,402,046 9/1968 96/74 3,411,904 11/196896/74 3,411,911 11/1968 .96/114 3,411,912 11/1968 Dykstra 96/114Millikan 96/74 Hara et a1. 96/74 Primary Examiner-Norman G. TorchinAssistant Examiner-J. P. Brammer Attorney, Agent, or FirmM. R.Chipaloski [5 7 ABSTRACT Photographic elements are disclosed whichcomprise a support having thereon at least two image dyeproviding layerunits which each contain a silver halide emulsion and a color coupler.The silver halide emulsion of one of the image dye-providing layer unitshas a substantially larger mean grain size than the silver halideemulsion of at least one other image dyeproviding layer unit and hasassociated therewith at least 10 mg./ft. of a nondiffusing anionicorganic compound. The image dye-providing layer units containing acoarse-grain emulsion and the nondiffusible anionic organic compoundexhibit high rates of silver formation when developed with acolor-developing agent such as a p-phenylenediamine.

18 Claims, No Drawings MULTICOLOR PHOTOGRAPHIC ELEMENTS CONTAININGCOARSE-GRAIN SILVER HALIDE EMULSIONS This invention relates tophotographic elements designed for producing a color image recordtherein and improved processes for producing image records inphotographic elements where development is effected with an aromaticprimary amino silver halide developing agent. In one aspect, thisinvention relates to the use of certain high-molecular-weight,nondiffusing, ani onic organic acids to increase the rate of developmentof a silver halide emulsion when developed with'a color-developingagent. In another aspect, this invention relates to photographic silverhalide elements comprising at least two image dye-providing layer unitswherein at least one of said image dyeproviding layer units contains asilver halide emulsion having an average grain size which is at least 50percent larger than the silver halide emulsion of the other imagedye-providing layer unit.

It is known in the prior art that color-developing agents such asaromatic primary amino compounds develop exposed silver halide at a muchslower rate than black-and-white developing agents such ashydroquinones, pyrazolidones, etc. While it may be possible to developthe same amount of silver in an exposed silver halide element witheither type of developing agent, it would be desirable to increase therate of development with a color silver halide developing agent.

It is also known in the art that certain photographic elements containlayers having fine-grain emulsions and layers containing coarse-grainemulsions, such as in color papers where the blue-sensitive emulsion isa coarse-grain emulsion and the spectrally sensitized greenandred-sensitive emulsions are fine-grain emulsions to obtain speeddifferential to blue light. Generally, the coarse-grain emulsiondevelops very slowly compared with the fine-grain emulsion whendeveloped with a eolordeveloping agent. In many instances it would bedesirable to develop all layers at a uniform rate, or at least toincrease the rate of development of the coarse-grain emulsion to providehigh silver formation at short development times.

I have now found that nondiffusible anionic organic acids can beincorporated in a photographic element in association with a silverhalide emulsion to increase the rate of development with a colordeveloper, especially to increase the rate of development of aslowdeveloping emulsion such as a coarse-grain emulsion.

Generally, the photographic elements in accordance with this inventioncontain immobile or nondiffusible, anionic organic compounds having acidgroups thereon and having an equivalent weight of at least 70 andpreferably between 100 and 300 based on said acid groups. The acidgroups can generally be sulfmic acid groups, sulfonic acid groups,carboxylic acid groups, phosphonic acid groups, phosphate groups.sulfate groups, and the like or salts thereof, and preferably the alkalimetal or alkaline earth salts thereof. In certain highly preferredembodiments, the anionic organic compounds are organic sulfonic acidssuch polymers containing sulfonic acid groups thereon.

In a highly preferred embodiment of this invention, multicolorphotographic elements can be made which comprise at least two imagedye-providing layer units which each contain a silver halide emulsionand a color coupler, said silver halide emulsion of at least one imagedye-providing layer unit having a mean grain size which is 0.5 micronlarger or 50 percent larger than the mean grain size of the silverhalide emulsion of another of said image dye-providing layer units,wherein said image dye-providing layer unit containing the silver halideemulsion of larger grain size has associated therewith a compounddifferent from said color coupler which is a nondiffusible anionicorganic acid. Preferably, the nondiffusible, anionic organic acidcompound is in association only with the coarse-grain silver halideemulsion and the remaining image dye-providing layer units containingfine-grain emulsions are substantially free of the nondiffusible anionicorganic acid compounds, and preferably are'substantially free of thenondiffusible, anionic organic acid compound.

In another highly preferred embodiment, the photographic elements ofthis invention comprises a support having thereon l a yellow imagedye-providing layer unit comprising a silver halide emulsion having amean grain size of at'least 0.8 micron and a yellow image dyeprovidingcolor coupler, (2) a magenta image dyeproviding layer unitcomprising asilver halide emulsion having a mean grain size of less than about 0.4micron and a magenta image dye-providing coupler, and (3 a cyan imagedye-providing layer unit comprising a silver halide emulsion having amean grain size of less than about 0.4 micron and a cyan imagedye-providing coupler, wherein a nondiffusible anionic organic com poundhaving acid groups thereon and having an equivalent weight of at least70, and preferably 100, based on acid groups is present in said yellowimage dyeproviding layer unit; preferably, said cyan and magenta dyeimage-providing layer units are substantially free of said anionicorganic compound or at least contain less than 5 mg./ft. of said anionicorganic compound.

In another preferred embodiment, this invention relates to photographicelements comprising at least two and preferably three imagedye-providing layer units comprising silver halide emulsions, wherein atleast one and preferably two of said image dye-providing layer unitscomprise at least a 40 percent stoichiometric excess of an imagedye-providing color coupler bas'ed on effective or developable silver,and preferably these layers also each contain less than 30 mg/ft? ofsilver halide based on silver.

Generally, the organic acids useful according to this invention arewater-soluble compounds which are nondiffusing or immobile asincorporated in the photographic element, and have an equivalent weightof at least and preferably between about 100 and 300 based on acidgroups. They can be incorporated in either their salt or free-acid form,but are preferably incorporated in the salt form such as with an alkalimetal salt. Whereas mobile compounds will generally migrate from layerto layer during the development process, the immobile organic sulfonieacids remain in the proximity of the coarse-grain silver halide duringthe entire development process.

In one embodiment, l have found that water-soluble polymeric compoundscontaining acid groups thereon and having a molecular weight of at least3000 and preferably at least 5000 can be used with coarse-grain silverhalide emulsions to provide improvements in accordance with thisinvention. Typical polymers of this type include the acrylic polymershaving acid groups thereon and comprise units of 3-methacryloyloxypropane-l-sulfonic acid. sodium salt;3-acryloyloxypropane-l-sulfonie acid, sodium salt; sodiummethacryloyloxyethyl sulfate; sodium methacrylate; and the like. Thepolymers can also be polystyrenes such as sulfonated polystyrene and thelike.

In another embodiment, the water-soluble polymers of this invention cancomprise units having acid groups thereon and units having hardenable orcrosslinking groups thereon, wherein the polymer can be crosslinked insitu after coating to provide a polymeric compound which is nondiffusingor immobile. Typical hardening groups which can be incorporated intopolymers of this type include 2-acetoacetoxyethyl methacrylate,2-12-(methacryloyloxy)ethyllisothiouronium methane sulfonate,N-cyanoacetyl-N'-methacryloyl hydrazine. N-methacryloyl-N-glycylhydrazine hydrochloride, 2- aminoethyl methacrylate hydrochloride andthe like. Typical useful polymers of this type include poly(N-isopropylaerylamide-- -3-methacryloyloxypropanel-sulfonic acid, sodiumsalt--2-acetoacetoxyethyl methacrylate poly( N- isopropylacrylamide---3-methacryloyloxypropanel -sulfonic acid, sodiumsalt--Z-acetoacetoxyethyl methacrylate; and the like, including polymerscontaining acid groups disclosed in U.S. Pats. No. 3,459,790 by Smithissued Aug. 5, 1969,

etc.

The concentration of the organic acid compound will depend upon theconcentration of the silver halide emulsion in the image dye-providinglayer unit. Generally, the organic acid is incorporated in an imagedyeproviding layer unit in concentrations of at least mg./ft. andpreferably at least mg./ft. and generally the anionic organic compoundis utilized in the image dye-providing layer in concentrations of atleast 50 per cent by weight of any other compound which is a bydrophilic colloid and which is generally used as a binder or peptizingagent for the silver halide, i.e., such as gelatin, polymeric peptizersor polymeric vehicles. In certain embodiments, the anionic organiccompound is a polymeric compound which is the sole binder or carriervehicle for the ingredients of the image dyeproviding layer unit.However, when the anionic organic acid compound constitutes over 75percent of the binder or carrier vehicle, it preferably containshardening or crosslinking groups to permit hardening to take place.

The anionic organic acid compound is located in the photographic elementin association with the image dye-providing layer units containing acoarse-grain silver halide emulsion. Generally, the anionic organiccompound is mixed with the silver halide emulsion prior to coating;however, it can also be coated in adjacent and preferably contiguouslayers. In most embodiments, it is desirable to locate the anionic acidmaterial within the image dye-providing layer unit whereby it will nothave a substantial effect on adjacent image dye-providing layer unitswhich contain smaller-grain silver halide emulsions.

The photographic elements of this invention containing the anionicorganic compounds in association with the coarse-grain emulsion layerscan generally be processed by any of the color-development processesused for processing silver halide-containing photographic elements. Therate of image dye production in image dye-providing layer unitscontaining coarse-grain silver halide emulsion will be enhanced sincecolor development occurs at a faster rate in coarse-grain emulsions witha color developer such as an aromatic primary amino color-developingagent.

In certain highly preferred embodiments, the photographic elements ofthis invention are especially useful to obtain uniform image dyeproduetionin development and amplification processes. such as thosedescribed in U.S. Ser. Nos. 189,289 by Bissonette filed Oct. 14, 1971,and 256,071 by Travis filed May 23, 1972, now U.S. Pat. 3,765,891, bothapplications being incorporated herein by reference. In one aspect ofthese processes, image dye is formed by contacting an imagewisedistribution of metallic silver with a cobalt- (lll) complex and aprimary aromatic amino silver halide developing agent wherein themetallic silver acts as a catalyst to generate oxidized color developer,which in turn reacts with a coupler to form the image dye. In processesof this type, it is very desirable to obtain substantial amounts ofmetallic silver in slowly developing, coarse-grain, silver halideemulsions before overdevelopment of the fine-grain silver halideemulsions occurs, so that catalytic production of oxidized developerwill occur only in the exposed areas of each respective layer. Theanionic organic acid compounds used in accordance with this inventionare water-soluble compounds as coated in the photographic element. Thewater-soluble polymers are to be distinguished from latexes andhydrophobic polymers and generally have a solubility in water at roomtemperature of at least 3 percent and preferably at least 5 percent byweight of water. The term water-soluble as used herein thus refers tothe property of the compound as coated regardless of whether it has beencrosslinked or hardened in the photographic element after coating.

The term anionic organic compound as used herein refers to thosecompounds which are anionic under the conditions of general use inphotography and preferably does not include amphoteric compounds.Preferably, the compounds exhibit anionic properties in the pH range offrom about 3 to about 1 1. Moreover, the anionic organic compounds arenonproteinaceous compounds; for example, the term does not includesubstances such as gelatin which is amphoteric and pro teinaceous. Instill one other aspect, the anionic compounds preferably have theequivalent weight as mentioned elsewhere herein, but can be furtherdefined as those compounds having an equivalent weight of less than 800and preferably less than 600 based on acid groups.

The silver halide emulsions used in accordance with this invention cancomprise. for example, silver chloride, silver bromide, silverbromoiodide, silver chlorobromide, silver chloroiodide, silverchlorobromoiodide crystals or mixtures thereof. The coarseand fine-grainemulsions can be prepared by any of the well-known techniques, e.g.,single-jet emulsions such as those described in Trivelli and Smith, ThePhotographic Jlll rnul, Vol. LXXlX, May, 1939 (pp- 330338), double-jetemulsions such as Lippmann emulsions, ammoniacal emulsions, thiocyanateor thioethcr ripened emulsions such as those described in U.S. Pats.Nos. 2,222,264 by Neitz et al. issued Nov. 19, 1940, 3,320,069 bylllingsworth issued May 16, 1967, and 3,271,157 by McBride issued Sept.6, 1966. Surface-image emulsions may be used or internal-image emulsionsmay be used such as those described in U.S. Pats. Nos. 2,592,250 byDavey et al. issued May 8, 1952, 3,206,313 by Porter et al. is-

l 1939. 2.541.472 by Kendall et a1. issued Feb/13. 1951.

3,367,778 by Berriman issued Feb. 6. 1968. 3.501.307 by lllingsworthissued Mar. 17. 1970. 2.563.785 by 'lvcs issued Aug. 7. 1951. 2.456953by Knott et a1. issued Dec. 21. 1948. and 2.861.885 by Land'issuedNov.25. 1958. British Patent 723.019 by Schouwenaars issued Feb. 2. 1955.and French Patent 1.520.821 by lllirlgsworth issued Mar. 4. 1968.Preferably. the emulsions are negative. developing-out-type. silverhalide emu lsions. I I

Generally. each of the color-providing layer units of the photographicelements contains a lightfsensitive silver salt which is preferably asilver halide. In one preferred embodiment. at least two of thecolor-providinglayer units each comprise a silver salt at aconcentration of up to 30 mg. of silver/ftF. Howeven whilethedevelopable silver halide is preferably present at conccntrations basedon silver of less than 3() mg./ft. it is possible to coat blendedemulsions at higher coverages within this embodiment. as long as no morethan3'0 mg./ft. of silver develops; for example. such emulsions maycontain silver halide grains which are relatiyely light-insensitive ormay contain development restrainers. such as with developmentinhibitor-releasing couplers. and still provide a photographic elementwhich is advantageously used in the various'processes as describedherein to produce improved image records. In some instances. emulsionscontaining relatively lightinsensitive grains or development inhibitorsare desirable to enable one to obtain more uniform coating coverage withless precise coating equipmcnt. as well as for other reasons. Thus.highly preferred photegraphic'elcments of this invention Contain atleast two colorproviding layer units.'each containing a silver halideemulsion. defined in terms ofeffective coverage and developability. asone which. when it is fully exposed and processed for about 1 minuteat100 F. in Developer A as follows: I

- -Color' Developer A water to 1 liter pH 10.1 at 24 (1 will provideless than 30 mg. of metallicsilver/ftf and preferably less than 15mg./ft. It is understoddthat the term effective silver" refers to thatamount of silver which is developed in this test and. that ratios ofcoupler to silver are based on effective silver which is produced bythis type of development when so specified herein.

6 In most instances. the quantity of effective silver as silver halidein the undeveloped. unexposed photographic element will be quite similar.to quantity of total silver present as silver halide. The fully exposedlayer containing silver halide emulsion is one which is exposed to Dmaxas is well-known in the art. for example. by exposure to a SQO-watt.30OQ K lamp for about 10 seconds (total exposure at the film plane 11.3X 10" ln certain embodiments. the emulsions of at least one imagedye-providing layer unit are coarse-grain silver halide emulsions andgenerally have a mean grain size of at least 0.8 micron. and preferablyat least 1.0 micron. Grain sizes can be measured by methods commonlyused in the art for this purpose. A typical procedurc is set forth .by'Loveland. Methods of Particle- Size Analysis". ASTM Symposimh on LightMicroscopy.

19 53. ppf94-122. or in chapter 2 of The Theory Qf thePhotographicPnicess. Mees and James. 3rd Ed. 1966).

published by MaicMillan Co. The grain size can be measured using theprojected areas of the grains or approximate diameter. When the grainsare substantially uni- :form in shape. the size distribution can beexpressed quite accurately as either diameter or projected area. Thesize-frequency relationshipcan be determined as disclosed in article byTrivelli and Smith entitled Empirical Relations betwcen Sensitometricand Size Frequency in Photographic Emulsion Series. The Film tographicJournal, Vol. LXXIX, 1949, pp. 330338.

The light scnsitive silver salts are generally coated in thecolor-providing layer units in the same layer with photographic colorcoupler. However. they can be coated in separate adjacent layers as longas the couinto adjacent color-providing layer units.

As used herein the terrn sphotographic color coupler. and imagedye-providing color coupler include any compound which reacts (orcouples) with the oxidation products of. primary aromatic aminodeveloping agent on photographic development to form animage dye. andare nondiffusible in a hydrophilic colloid binder (e.g.. gelatin) usefulfor photographic silver halidesand also those couplers which provideuseful image dyes when reacted with oxidized primary aromatic aminodeveloping agents such as by a coupler-release mechanism. The couplerscan form diffusible or nondiffusible dyes]. Typical preferred colorcouplers include phenolic. '5-py razolone and open-chain ketomethylenecouplers S pecific cyan. magenta and yellow color couplerswhich can. beemployed in the practice of this invention are described in'Graham eta1. U.S. Pat. l\lo. 3.046.129 issued Jan. 24. 1962. column 15. line 45.through column 18. line 51. which disclosure is incorporated herein byreference. Such color couplers can be dispersed in convenient manner.such by using the solvents andthe techniques described in U.S. Pats.Nos. 2,322,027 byJelley et a1. issued June 15, .1943, or 2.894.171, byFierke et a1. issued July 30. 1957. When coupler solvents are employed.the most useful weight ratios of color coupler to coupler solvent range.from about] :3 to 1:0.1. The useful couplers include Fischer-typeincorporated couplers such as those described in Fiescher. US. Pat. No.1.055.155 issued Mar. .4. l9l3.-and particularly nondiffusibleFieschertype couplers containing branched carbon chains, e.g., thosereferred to in the references cited in Frohlich et al. U.S. Pat. No.2.376.679 issued May 22. I945. column 2, lines 50-60. Particularlyuseful in the practice of this invention are the nondiffusible colorcouplers which form nondiffusible dyes.

In certainpreferred embodiments, the incorporated couplers in the layerunits of this invention are waterinsoluble color couplers which areincorporated in a coupler solvent which is preferably a moderately polarsolvent. Typical useful solvents include tri-o-cresyl phosphate,di-n-butyl phthalate. diethyl lauramide. 2.4- diarylphenol. liquid dyestabilizers as described in an article entitled Improved PhotographicDye Image Stabilizer-Solvent Product Licensing [Ill/0X, Vol. 83. pp.2629. March, l97l, and the like. The elements containing couplersolvents appear also to aid in imbibing color developer in thoseprocesses where it is carried from a developer bath into an amplifierbath.

The term nondiffusible" used herein as applied to the anionic acids, thecouplers. and the products derived from couplers has the meaningcommonly applied to the term in color photography and denotes materialswhich for all practical purposes do not migrate or wander throughphotographic hydrophilic Colloid layers. such as gelatin. particularlyduring processing in aqueous alkaline solutions. The same meaning isattached to the term immobilc. The terms diffusible" and mobile have theconverse meaning. I I

The photographic elements of this invention, as defined above. comprisea support having thereon image dye-providing layer units. A multicolorphotographic element comprises at least two of said image dyeprovidinglayer units which each records light primarily in different regions ofthe light spectrum. The layer unit comprises a light-sensitive silversalt. which is generally spectrally sensitized to a specific region ofthe light spectrum, and has associated therewith a photographic colorcoupler. In certain preferredembodiments. the color-providing layerunits are continuous layers which are effectively isolated from otherlayer units by barrier layers. spacer layers. layers containingscavengers for oxidized developer and the like to prevent anysubstantial color contamination between the image dyeproviding layerunits. The effective isolation of the layer units is known in the artand is utilized to prevent contamination in many commercial colorproducts.

In certain preferred embodiments. the photographic elements of thisinvention comprise a support having thereon at least one imagedye-providing layer unit containing a light-sensitive silver salt.preferably silver halide. having associated therewith a stoichiometricexcess of coupler of at least 40 percent and at least preferably 70percent. The equivalency of color couplers is known in the art; forexample, a 4-equivalent coupler requires 4 moles of oxidized colordeveloper. which in turn requires development of 4 moles of silver, 'toproduce 1 mole of dye. Thus, for a stoichiometric reaction with silverhalide, l-equivalent weight of this coupler will be 0.25 mole.Image-providing units of this embodiment comprise at least a 40 percentexcess of the equivalent weight of image dye-providing color couplerrequired to react on a stoichiometric basis with the de velopable silverand preferably a 70 percent excess of said coupler. In one highlypreferred embodimenuat least a 1 10 percent excess of the coupler ispresent in said dye image-providing layers based on silver. Preferably,the coupler-to-silverratio is based on effective silver as definedherein. The ratio can also be defined as an equivalent excess with acoupler-to-silver ratio of at least l.4:l. and preferably at least 1.7:l(i.e., 2:1 being a l00'per cent excess). In certain preferredembodiments. the photographic color couplers are employed in the imagedye-providing layer units at a concentration of at least 3 times. suchas from 3 to 20 times, the weight of the silver in the silver halideemulsion. Weight ratios 'of coupler-'to-silver coverage which areparticularly useful are from 4 to 15 parts by weight coupler to 1 partby weight silver. Advantageously, the coupl er is present in an amountsufficient to give a density of at least L7 and preferably at least 2.0.Preferably. the difference between the maximum density and the minimumdensity (which can comprise unbleached silver) is at least 0.6 andpreferably at least 1.0.

It is realized that the density of the dye may vary with the developingagent combined with the respective coupler. and accordingly the quantityof coupler can be adjusted to provide the desired density. Preferably,each layer unit contains least I X 10 moles/ft. of color coupler.

Advantageously, the photographic color couplers utilized arc sclected sothat they will give a good neutral dye image. Preferably, the cyan dyeformed has its major visible light absorption between about 600 and 700nm., the magenta dye has its major absorption between about 500 and 600nm., and the yellow dye has its major absorption between about 400 and500 nm.

The photographic elements of this invention are particularly useful inthe processes disclosed in Bissonette, U.S. Ser. No. l89, 289, entitledImage-Forming Processes and Compositions, filed Oct. 14, I971, andincorporated herein by reference. Generally, in this process a redoxreaction between an oxidizing agent and a reducing agent is utilized toproduce a change in light value. This change in light value can comeabout directly by a change in the light value of either the oxidizingagent or reducing agent. Alternatively, the redox reaction can result inone or more reaction products which can react with each other or withanother component, such as a reactive species, to produce a change inlight value. In another variation. the reactivity of the reactivespecies can be reduced imagewise by one of the reaction products of theredox reaction. The redox reaction which takes place when the elementsare processed by this procedure occurs at a catalytic surface. Thecatalyst is metallic silver which, of course, can be produced bydevelopment of silver halide which contains a latent image. The catalystappears to promote redox reaction in true catalytic fashion The amountof redox reaction products is not limited by the amount of catalystpresent. since the catalyzed redox reaction .of this invention does notproceed on a stoichiornetric basis with respect to the catalyst.

Oxidants preferred in the practice of this process are the metalcomplexes, such as a transition metal complex. e.g., a Group VIII metalcomplex. or a complex of a metal of Series 4 of the periodic tableappearing on pp. 54 and 55 of Langes Handbook of Chemistry, 8th Edition,published by HandbookPublisher', Inc.. Sandusky. Ohio. I952. Suchcomplexes feature a molecule having a metallic atom or ion. Thismetallic atom or ion issurrounded by a group of'atoms. ions or othermolecules which are generically referred to as ligands. The metallicatom or ion in the center of these complexes is a Lewis acid; theligands are Lewis bases. Werner complexes are well-known examples ofsuch complexes. The useful metal salts are typically capable of existingin at least two valent states.

Preferred metal complexes in accordance with this process havecoordination numbers of 6. and are known octahedral complexes. Cobaltcomplexes are especially useful in the practice of this invention. Mostsquare planar complexes (which have a coordination number of 4) arerather labile, although some Group VIII metal square planar complexes,particularly platinum and palladium square planar complexes, exhibitinertness to rapid ligand exchange.

A wide variety of ligands can be used with a metal ion to form suitablemetal complexes. Nearly all Lewis bases (i.e.. substances having anunsharedpair of electrons) can be ligands in metal complexes. Sometypical useful ligands include the halides, e.g., chloride. bromide,fluoride, nitrite, water, amino, etc., as we] as such common ligands asthose referred to-by Basolo and Pearson in Mechanisms of Inorganic-Reactions, a Study Qf A1010! Comp/Laws and Solutions, 2nd Edition, 1967,published by John Wiley and Sons, p. 44. The lability of a complex isinfluenced by the nature of the ligands selected in forming saidcomplex.

Particularly useful cobalt complexes have a coordination number of 6 andhave a ligand selected from the group consisting of ethylenediamine(en),diethylenetriaminc( dien triethylenetctraamine(trien amine(NH;;).nitrate. nitrite, azide, chloride, thiocyanate, isothioeyanate, water,carbonate, and propylenediam i ne(tn). The preferred cobalt complexescomprise l at least 2 ethylenediamine ligands or (2) at least 5 ammineligands or (3) l triethylenetetraamine ligand. Es-

pecially useful are the cobalt hexammine salts (e.g.. the

chloride, bromide, sulfite, sulfate, perchlorate, nitrite and acetatesalts)v Some other specific highly useful eobalt complexes include thosehaving one of the following formulas: [Co( NH;,) -,H O]X; lCo(NH ).-,C;;]X; l zi )s IX; l NH3)4CO3]X; [CO( en )3]X;

[Co(tn) en) 1X; wherein X represents one or more anions determined bythe charge neutralization rule. Complexes containing oxidized noblemetals or ferromagnetic metals, such as complexes of Cr', Fe', Rh', Pt.Pd and Ir', which have reactivities similar to the complexes listedabove, could be used in the practice of this invention. The redoxequilibra published in Stability Constants of Metal-Ion Comp/ates,Sillen and Martcll, published by The Chemical Society, Burlington House,London, Eng. (1964), indicate that other complexes have reactivitiesgenerally similar to the cobalt complexes mentioned above.

Numerous reducing agents can be utilized in carrying out the sameprocess. The reducing agents utilized herein undergo redox reaction withthe oxidizing agent at a catalytic surface. Especially preferredreducing agents are those which reduce silver halide to metallic silver,such as those which are capable of developing imagewise-exposedlight-sensitive photographic silver halidev In certain embodiments, thereducing agent used in this process is an aromatic primary aminocolor-developing agent such as p-phenylenediamine. Color-developingagents which can be used include 3- acetamido-4-amino-N,N-diethylaniline, 4-amino-N- ethyl-N-B-hydroxyethylaniline sulfate,N,N-diethyl-pphenylencdiamine, Z-amino-5-diethylamiriotoluene,N-ethyl-N-B-methanesulfonamidoethyl3-methyl-4- aminoaniline,4-amino-N-ethyl-3-methyl-N-(,B-sulfoethyl )aniline, and the like. seeBent et al., JACS, Vol. 73

pp. 3100-3l25 1951 and Mees and James, The Theory oft/1e PhotographicProcess, 3rd Edition, 1966, published by MacMillan Co., New York, pp.27831 1, for further typical, useful developing agents.

In one highly preferred embodiment, aromatic primary aminocolordeveloping agents which provide good results in this process are4-amino-N,N- diethylaniline hydrochloride, 4-amino-3-methyl-N,N-diethylaniline hydrochloride, 4-amino-3-methyl-N- ethylN-,8(methanesulfonamido)ethylaniline sulfate hydrate,4-amino-3.-methyl-,N-ethyl-N-,B hydroxyethylaniline sulfate,4-amino-3-methylamino- N,N-diethylaniline sulfate hydrate, 4-amino-3-methoxy-l I-ethyl-l l-,l5-hydroxyethylaniline hydrochloride,4-amino-3-B-( methanesulfonamido )ethyl-N,N diethylaniline'dihydrochloride and 4-amino-N-ethyl-N- (Z-methoxyethyl )-m-toludinedi-p-toluenesulfonate.

In certain embodiments, developers other than pphenylenediamines andspecifically black-and-white developing-agents can be either.used in thedeveloper composition or incorporated in the photographic elements ofthis invention to provide further improvements in photographicdevelopmentproperties. In some instances, the rate of development of acoarsegrain silver'halide emulsion is further'increas ed by thecombination of the anionic organic'compounds and black-and-whitedeveloping agents. T

The invention can be further illustrated by the following examples. Theinherent viscosities referred to in the examples are measured ataconcentration of 0.25 g. of polymer/deciliter of solution at 25 C. usinga 0. l N sodium chloride solution as a solvent.

EXAMPLE 1,

Two photographic elements are prepared as follows:

Element A: a

l. papersupport: I

2. layer containing a silver chlorobromide e'mulsion 1.2 micron meangrain size) at mg. of 'Ag/ftl l-()() mg./ft. of the coupleroz-pivalyl-4-( 4- benzyloxyphenylsulfonyl )phenoxy-Z-chloro-S-'[ 'y-2,4-di-tert-amylphenoxy )butyramido lacetanilidc dispersed in mg./ft."and di-n-butyl phthalate and 200 mg./ft. 'of gelatin.

Element B:

Same as Element A wherein 100 'm'g./ft. of gelatin is replaced in layer2 with 100 mg./ft. of'copoly(N- isopropylacrylamide--'-3methacrylo'yloxypropanel -sulfonic acid, sodiumsalt--2-acetoacetoxyethyl methacrylate) (7:2:0.25'molar)('inh'erent'viscosity of 0.48

'Elements A and B are exposed to a test object and processed for 3%, 7and 14 minutes in a developer of the composition:

water benyyl alcohol hydroxylamine sulfate NaBr 4-amin o-Nethyl-N-(2methoxyethyl m toluidine di-paraioluenesultbnate I -Continued Na Cowater to l liter; pH 10.]

Following development. the elements are bleachfixed, washed andstabilized. Element B has developed almost twice as rapidly as ElementA.

EXAMPLE 2 Two photographic elements are prepared as follows: Element A:

1. paper support;

2. layer containing a silver chlorobromide emulsion 1.2 microns meangrain size) at 20 mg. of Ag/ftF, 100 mg./ft. of the couplera-pivalyl-4-(4- benzyloxyphenylsulfonyl )phenoxy-IZ-chloro-S-l y-(2,4-di-tert-amylphenoxy )butyramido laeetanilide dispersed in 25mg./ft. of di-n-butyl phthalate and 200 mg./ft. of gelatin.

Element B:

Same as Element A except 200 mgjft. of sulfonated polystyrene (preparedby sulfonation of polystyrene having a MW of 60,0()()l00,()) is added tolayer 2.

Each coating is exposed on a test object and processed for l, 2 and 3 /2minutes in a developer as mentioned in Example 1 which additionallycontains L6 g./l. of lCo(NH -,);;]Cl;,. Following development. thecoatings are bleach-fixed, washed and stabilized. Element B hasdeveloped nearly twice as rapidly as Element A despite its greaterthickness. but at the longer development time both coatings haveessentially identical curve shapes and speed.

The development acceleration effect is tested with light-sensitiveelements where the concentration of sulfonated polystyrene is lowered.Development acceleration is observed at concentrations as low as 10mg./ft. but preferably the concentration is at least 25 mg/ftf toobserve appreciable development acceleration effects.

The use of the sulfonated polystyrene is also tested in other layers andit is found that best results are obtained when the sulfonic acidcompound is incorporated in the emulsion layer.

Similar results are obtained when 200 mg. of the following polymers areadded to layer 2 of Element A and hardened with formaldehyde; poly( N-isopropylacrylamidc--3-acryloyloxypropanel -sulfonic acid, sodiumsalt--Z-acetoacetoxyethyl methacrylate) (7:4:0.25 by molar ratio); poly(N- isopropylacrylamidc-- -3-methacryloyloxypropane-l-sulfonic acid,sodium salt--2-acctoacetoxyethyl methacrylate) (7:2:0.25 by molarratio); poly( Nisopropylacrylamide---3-methacryloyloxypropane-l-sulfonic acid, sodiumsalt--2-acetoacetoxyethyl methacrylate) (2:l2:l by

molar ratio); polymethacrylic acid, sodium salt; and polysodiummcthacryloyloxyethyl sulfate.

EXAMPLE 3 Photographic multilayer elements are made as follows:

Element A:

l. polyethylene-coated paper support; 2. layer containing ablue-sensitive silver halide emulsion 1.2 microns mean grain size) at 16mg. of sil- 12 ver/ft.'-. gelatin at l22 mg /ft. and a yellow coupler.ae-pivalyl-4-(4- bcnzyloxyphenylsulfonyl )phenoxy-Z-chloro-S-ly-(2'.4-di-tert-amylphenoxy )butyramido laeetanilide, at 60 mg./ft.dispersed in di-nbutyl phthalate at 15 mg./ft.'

3. layer containing lOO mg./ft.' of gelatin;

4. layer containing a green-sensitive silver halide emulsion (0.3 micronmean grain size) at 10 mg. of silver/ft. gelatin at 132 mg./ft. and amagenta coupler, l-( 2,4,6-trichlorophenyl )-3- {5-[ a-(3-tertbutyl-4-hydroxyphenoxy )tetradeeanamido -2- chloroanilino}-4-pyrazolone, at 25 mg/ft. dispersed in tricresyl phosphate at 12.5mg./ft.

5. a layer containing 160 mg/t't. of gelatin;

6. a layer containing a red-sensitive silver halide emulsion (0.3 micronmean grain size) at 6 mg. of silver/ftF, gelatin at 90 mg./ft. and acyan coupler, 2-[ a-( 2,4-di-tert-amylphenoxy )butyramido ]-4,6-dichloro-5-methylphenol, at mg./ft. dispersed in di-n-butyl phthalate at17.5 mg./ft.

7. a layer containing gelatin at 100 mg./ft. Element B:

This element is prepared exactly as Element A except the layercontaining the coarse-grain, bluesensitive, silver halide emulsion alsocontains 122 mg/ft. of poly( 3-methaeryloxyloxypropanel sulfonic acid,sodium salt), having an inherent viscosity of 0.15.

Elements A and B are exposed through a multicolor,

graduated-density test object and processed in the following sequence:

Process l Process 2 Process 3 (seconds) (seconds) (seconds)color-develop 3U amplify 9U 9U 9U bleach-fix 60 (10 60 Wash 90 90 Theprocessing baths have the following compositions'.

water to 1 liter: pH 4.5

The samples are then sensitometrically evaluated by recording the H andD curves of the yellow. magenta and cyan dye images. In Process 1,Element B contains substantially more yellow dye than Element A. InProcess 2, Element B contains more yellow dye than Element A and alsoexhibits a distinct plateau region on the H and D curve at the samedensity and has substantially the same contrast as the cyan and magentacurve. In Process 3, there is slightly more yellow dye in Element B thanElement A. In all of the processes the dye yield in the cyan and magentadye layers does not vary substantially in the Dmax areas, but the Dminareas exhibit more dye at the longer process time. Thus, it is apparentthat the incorporated anionic polymer has enabled one to obtain high dyeproduction in the coarsegrain layer without substantial dye productionin the Dmin areas of finegrain emulsions which may be caused byoverdevelopment of those layers.

Although the invention has been described in considerable detail withparticular reference to certain preferred embodiments thereof,variations and modifications can be effected within the spirit and scopeof the invention.

I claim:

1. A photographic element comprising a support having an imagedye-providing layer unit comprising a finegrain silver halide emulsionhaving associated therewith a color coupler and another dyeimageproviding layer unit containing a coarse-grain silver halideemulsion which has a mean silver halide grain size at least 50 percentlarger than the mean grain size of said fine-grain emulsion, andassociated therewith a color coupler and at least mg/ft. of a compounddifferent from said color coupler which is a nondiffusible anionicorganic polymeric acid having an equivalent weight of at least 100 andless than 800 based on acid groups; and wherein said fine grain emulsionis substantially free of said non-diffusible anionic organic polymeracid compound.

2. A photographic element according to claim 1 wherein saidnondiffusible organic acid is a polymer compound containing sulfonicacid groups thereon.

3. A photographic element according to claim 1 wherein said coarse-grainsilver halide emulsion has a mean grain size of at least 0.8 micron andsaid anionic organic compound has an equivalent weight of less than 300.

4. A photographic element according to claim 1 wherein said fine-grainemulsion has a mean grain size of less than 0.4 micron and saidcoarse-grain emulsion has a mean grain size of at least 1.0 micron.

5. A photographic element according to claim 1 wherein said imagedye-providing layer unit containing said fine-grain emulsion comprisesat least a 40 percent stoichiometrie excess of said color coupler basedon silver.

6. A photographic element according to claim 1 which comprises at leasttwo of said image dyeproviding layer units which each contain fine-grainsilver halide emulsion at a coverage of less than mg./ft. based onsilver.

7. A photographic element according to claim 1 wherein said anionicorganic compound is an anionic sulfonic acid and is present in aconcentration of at least l0 mg./ft.

8. A photographic element according to claim 1 wherein said anionicorganic acid is a polymeric compound having a molecular weight of atleast 3000.

9. A photographic element according to claim 1 wherein said anioniccompound is a polymeric compound comprising units having sulfonic acidgroups thereon and units having crosslinking groups thereon.

10. A photographic element comprising a support and having thereon (l) ayellow image dye-providing layer unit comprising a silver halideemulsion having a mean grain size of at least 0.8 micron and a yellowimage dye-providing color coupler, (2) a magenta image dye-producinglayer unit comprising a silver halide emulsion having a mean grain sizeof less than 0.4 micron and a magenta image dye-providing coupler, and(3) a cyan image dye-providing layer unit comprising a silver halideemulsion having a mean grain size of less than 0.4 micron and a cyanimage dye-providing coupler, wherein a nondiffus ible anionic organicpolymer compound having sulfonic acid groups thereon and having anequivalent weight of at least based on sulfonic acid groups is presentin said yellow image dye-providing layer unit in a concentration of atleast 10 mg./ft. and wherein said magenta and cyan image dye providingunits are substantially free of said nondiffusible anionic organicpolymeric acid compounds.

11. A photographic element according to claim 10 wherein said anionicorganic compound is an acrylic polymer.

12. A photographic element according to claim 10 wherein said anionicorganic compound is present in said yellow image dye-providing layerunit in a concentration of at least 25 mg./ft. and said cyan and magentadye image-providing layer units contain less than 5 mg./ft. of saidanionic organic compound.

13. A photographic element-according to claim 10 wherein said anionicorganic compound has an equivalent weight of less than 800 and ispresent in said yellow image dye-providing layer unit in a concentrationof at least 25 mg./ft.

14. A photographic element according to claim 10 wherein said magentaand cyan image dye-providing layer units contain at least 2140 percentstoichiometric excess based on effective silver.

15. A photographic element according to claim 10 wherein said anionicorganic compound is a poly(3- methacryloyloxypropanel-sulfonic acid).

16. A photographic element according to claim 10 wherein said anioniccompound is poly(N- isopropylacrylamide--3-acryloyloxypropanel-sulfonieacid, sodium salt--2-acetoacetoxyethyl methacrylate).

17. A photographic element according to claim 10 wherein said anioniccompound is poly(N- isopropylacrylamide-- -3-methacryloyloxypropane 1-sulfonic acid, sodium salt-Z-acetoacetoxyethyl methacrylate 18. Aphotographic element according to claim 10 wherein said anionic organiccompound in said yellow image dye-providing layer unit in a compounddifferent from said image dye-providing color coupler.

' age UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,9 B 3 Dated September 9, 1975 lnven m-( Rowland George Mowrey It iscertified that: error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 3, line 62, after "organic", -acidshould be added.

Column 6, line 67, 'Flescher", should read --Fischer.

Q Column 6, line 68, "Fiescher", should read --Fischer--.

Column 9, line 19, "we l" should read --well-.

Column l L, line 15, "producing" should read -providing--.

' Column l I, line 60, "organic" should be deleted.

Column l I, line 61, "in", should read --is-.

' Engned and Ewalcd this sixth D y of January 1976 [SEAL] Attest: O

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Patentsand Trademarks

1. A PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING AN IMAGEDYE-PROVIDING LAYER UNIT COMPRISING A FINE-GRAIN SILVER HALIDE EMULSIONHAVING ASSOCIATED THEREWITH A COLOR COUPLER AND ANOTHER DYEIMAGE-PROVIDING LAYER UNIT CONTAINING A COARSE-GRAIN SILVER HALIDEEMULSION WHICH HAS A MEAN SILVER HALIDE GRAIN SIZE AT LEAST 50 PERCENTLARGER THAN THE MEAN GRAIN SIZED OF SAID FINE-GRAIN EMULSION, ANDASSOCIATED THEREWITH A COLOR COUPLER AND AT LEAST 10 MG./FT.2 OF ACOMPOUND DIFFERENT FROM SAID COLOR COUPLER WHICH IS A NONDIFFUSIBLEANIONIC ORGANIC POLYMERIC ACID HAVING AN EQUIVALENT WEIGHT OF AT LAST100 AND LESS THAN 800 BASED ON ACID GROUPS: AND WHEREN SAID FINE GRAINEMULSION IS SUBSTANTIALLY FREE OF SAID NON-DIFFUSIBLE ANIONIC ARGANICPOLYMER ACID COMPOUND.
 2. A photographic element according to claim 1wherein said nondiffusible organic acid is a polymer compound containingsulfonic acid groups thereon.
 3. A photographic element according toclaim 1 wherein said coarse-grain silver halide emulsion has a meangrain size of at least 0.8 micron and said anionic organic compound hasan equivalent weight of less than
 300. 4. A photographic elementaccording to claim 1 wherein said fine-grain emulsion has a mean grainsize of less than 0.4 micron and said coarse-grain emulsion has a meangrain size of at least 1.0 micron.
 5. A photographic element accordingto claim 1 wherein said image dye-providing layer unit containing saidfine-grain emulsion comprises at least a 40 percent stoichiometricexcess of said color coupler based on silver.
 6. A photographic elementaccording to claim 1 which comprises at least two of said imagedye-providing layer units which each contain fine-grain silver halideemulsion at a coverage of less than 30 mg./ft.2 based on silver.
 7. Aphotographic element according to claim 1 wherein said anionic organiccompound is an anionic sulfonic acid and is present in a concentrationof at least 10 mg./ft.2.
 8. A photographic element according to claim 1wherein said anionic organic acid is a polymeric compound having amolecular weight of at least
 3000. 9. A photographic element accordingto claim 1 wherein said anionic compound is a polymeric compoundcomprising units having sulfonic acid groups thereon and units havingcrosslinking groups thereon.
 10. A photographic element comprising asupport and having thereon (1) a yellow image dye-providing layer unitcomprising a silver halide emulsion having a mean grain size of at least0.8 micron and a yellow image dye-providing color coupler, (2) a magentaimage dye-producing layer unit comprising a silver halide emulsionhaving a mean grain size of less than 0.4 micron and a magenta imagedye-providing coupler, and (3) a cyan image dye-providing layer unitcomprising a silver halide emulsion having a mean grain size of lessthan 0.4 micron and a cyan image dye-providing coupler, wherein anondiffusible anionic organic polymer compound having sulfonic acidgroups thereon and having an equivalent weight of at least 100 based onsulfonic acid groups is present in said yellow image dye-providing layerunit in a concentration of at least 10 mg./ft.2 and wherein said magentaand cyan image dye providing units are substantially free of saidnon-diffusible anionic organic polymeric acid compounds.
 11. Aphotographic element according to claim 10 wherein said anionic organiccompound is an acrylic polymer.
 12. A photographic element according toclaim 10 wherein said anionic organic compound is present in said yellowimage dye-providing layer unit in a concentration of at least 25mg./ft.2 and said cyan and magenta dye image-providing layer unitscontain less than 5 mg./ft.2 of said anionic organic compound.
 13. Aphotographic element according to claim 10 wherein said anionic organiccompound has an equivalent weight of less than 800 and is present insaid yellow image dye-providing layer unit in a concentration of atleast 25 mg./ft.2.
 14. A photographic element according to claim 10wherein said magenta and cyan image dye-providing layer units contain atleast a 40 percent stoichiometric excess based on effective silver. 15.A photographic element according to claim 10 wherein said anionicorganic compound is a poly(3-methacryloyloxypropane-1-sulfonic acid).16. A photographic element according to claim 10 wherein said anioniccompound is poly(N-isopropylacrylamide--3-acryloyloxypropane-1-sulfonicacid, sodium salt--2-acetoacetoxyethyl methacrylate).
 17. A photographicelement according to claim 10 wherein said anionic compound ispoly(N-isopropylacrylamide--3-methacryloyloxypropane-1-sulfonic acid,sodium salt--2-acetoacetoxyethyl methacrylate).
 18. A photographicelement according to claim 10 wherein said anionic organic compound insaid yellow image dye-providing layer unit in a compound different fromsaid image dye-providing color coupler.